# Homework Help: Basic circuit question

1. May 27, 2013

### masum79

Hello
I am new to the forum as well as a new EE student. Can't figure it out this particular diagram in terms of how to find an equivalent resistance. Any kind help would be very very appreciated.
Bila

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2. May 27, 2013

### SammyS

Staff Emeritus
Hello masum79. Welcome to PF !

This thread has been moved to the Engineering Homework section.

Before we can help with homework, you must show some effort towards a solution.

Hint: No current flows across the gap marked v0 .

[ IMG]https://www.physicsforums.com/attachment.php?attachmentid=59042&d=1369634684[/PLAIN]

3. May 27, 2013

### masum79

Dear SammyS, Thank you for the lead.
I figure it out since there is not current going through. So, I found Vo to be +2.0V. But my friend said it would be -2.0V. That one I am not sure why It would be minus instead of plus.

--Bila

4. May 27, 2013

### gnurf

How did you get +2V?

5. May 27, 2013

### SammyS

Staff Emeritus
What is the voltage drop across (either) 300 Ω resistor?

What is the voltage drop across (either) 200 Ω resistor?

6. May 28, 2013

### CWatters

There is only one 200Ω resistor.

The magnitude of the voltage difference is indeed 2V. The question now is the polarity.

The circuit diagram tells you which side is +ve _if_ Vo is a positive number. The OP needs to work out which side actually is more positive than the other.

7. May 28, 2013

### SammyS

Staff Emeritus
DUH !

I've got to proof my posts better !

Too much cut & paste .